I wouldn't consider myself very nervous or high-strung, but considering how easily I get startled or scared, I may have to re-think that.
The Mister is very light on his feet, and at least once a day, he comes up behind me and scares the shit out of me. Not on purpose, mind you, just because I haven't heard him and he starts talking to me when I didn't know he was there. I've suggested he start wearing a bell, and he's suggested that I get my hearing checked.
It's happened a few times at work, too. The counter where I mix the colour formulas makes me stand with my back to the door, and inevitably someone comes in the mixing room, thinking I've heard them, and starts talking to me. I jump out of my skin and suffer a mild coronary, and then I answer their question. We had a new assistant one day, who did that while introducing himself to me. He said it was the best first day he ever had at any job.
When I was a teenager, someone gave me a life-sized poster of Humphrey Bogart for my birthday. I hung it on the inside of my bedroom door, but had to take it down after a couple of weeks; I kept waking up in the middle of the night in a mild seizure because I thought there was a man standing in my doorway. It would take ages for my adrenal glands to calm down and let me go back to sleep.
I never had to share a room with anyone much, and was used to sleeping by myself. When the Mister and I first got married, I had a couple of incidents where I'd wake up a bit and then leap out of bed in fear when I realized I could hear someone else breathing...."there's someone in the room with me!!" Then I'd remember I was married. The Mister can laugh about it now, but was really pissed back then. Have all the panic attacks you want, but don't mess with the Mister's sleep.
Today I managed to scare myself. I was awake really early this morning, so I got up to go out in the living room to read for a bit, planning on going back to bed. I turned on the light in the living room, and then went to find my book, and as I came back into the living room, caught a glimpse of my reflection in the window and for a split second was convinced there was someone outside looking in. In the exact same bathrobe as me. It scared the snot out of me.
I'm not sure if I need Valium or new glasses.